Devices for imaging body cavities or passages in vivo are known in the art and include endoscopes and autonomous encapsulated cameras. Endoscopes are flexible or rigid tubes that pass into the body through an orifice or surgical opening, typically into the esophagus via the mouth or into the colon via the rectum. An image is formed at the distal end using a lens and transmitted to the proximal end, outside the body, either by a lens-relay system or by a coherent fiber-optic bundle. Alternatively, the endoscope might record an image electronically at the distal end, for example using a CCD or CMOS array, and transfer the image data as an electrical signal to the proximal end through a cable. Because of the difficulty traversing a convoluted passage, endoscopes cannot easily reach the majority of the small intestine and special techniques and precautions, that add cost, are required to reach its entirety. The cecum and ascending colon also require significant effort and skill to reach with an endoscope. An alternative in vivo image sensor that addresses many of these problems is a capsule endoscope. A camera is housed in a swallowable capsule, along with a radio transmitter for transmitting data, primarily comprising images recorded by the digital camera, to a base-station receiver or transceiver and data recorder outside the body. Another autonomous capsule camera system with on-board data storage was disclosed in the U.S. patent application Ser. No. 11/533,304, filed on Sep. 19, 2006.
For the above in vivo devices, a large amount of image data is collected traversing through a lumen in the human body such as the gastrointestinal (GI) tract. The images captured, along with other information, are stored in the on-board archival memory inside the capsule camera. The archival memory may come in various forms of non-volatile memories. After the capsule camera exits from the anus, it is retrieved to recover the data stored on-board. In a conventional approach, it would require a fairly expensive data access system that includes opening the capsule and docking to it. Because of the requirement to open the capsule and align contact pins to pads in the capsule, some degree of mechanical complexity is inevitable. Therefore, such tasks usually are performed by specially trained persons. It is desirable to develop a new system that allows data retrieval from the capsule camera without opening the sealed enclosure. Furthermore, it is desired that the new system can operated be easily and quickly so that data retrieval from the capsule camera can be performed in any typical medical service environment.